include/media/v4l2-fh.h

   1 /*
   2  * v4l2-fh.h
   3  *
   4  * V4L2 file handle. Store per file handle data for the V4L2
   5  * framework. Using file handles is optional for the drivers.
   6  *
   7  * Copyright (C) 2009--2010 Nokia Corporation.
   8  *
   9  * Contact: Sakari Ailus <sakari.ailus@maxwell.research.nokia.com>
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License
  13  * version 2 as published by the Free Software Foundation.
  14  *
  15  * This program is distributed in the hope that it will be useful, but
  16  * WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  * General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  23  * 02110-1301 USA
  24  */
  25
  26 #ifndef V4L2_FH_H
  27 #define V4L2_FH_H
  28
  29 #include <linux/list.h>
  30
  31 struct video_device;
  32 struct v4l2_events;
  33
  34 struct v4l2_fh {
  35         struct list_head        list;
  36         struct video_device     *vdev;
  37         struct v4l2_events      *events; /* events, pending and subscribed */
  38 };
  39
  40 /*
  41  * Initialise the file handle. Parts of the V4L2 framework using the
  42  * file handles should be initialised in this function. Must be called
  43  * from driver's v4l2_file_operations->open() handler if the driver
  44  * uses v4l2_fh.
  45  */
  46 int v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev);
  47 /*
  48  * Add the fh to the list of file handles on a video_device. The file
  49  * handle must be initialised first.
  50  */
  51 void v4l2_fh_add(struct v4l2_fh *fh);
  52 /*
  53  * Remove file handle from the list of file handles. Must be called in
  54  * v4l2_file_operations->release() handler if the driver uses v4l2_fh.
  55  */
  56 void v4l2_fh_del(struct v4l2_fh *fh);
  57 /*
  58  * Release resources related to a file handle. Parts of the V4L2
  59  * framework using the v4l2_fh must release their resources here, too.
  60  * Must be called in v4l2_file_operations->release() handler if the
  61  * driver uses v4l2_fh.
  62  */
  63 void v4l2_fh_exit(struct v4l2_fh *fh);
  64
  65 #endif /* V4L2_EVENT_H */